Mundulla house Packer house at Mundulla, south-east S.A. steel portal roof fixed to limestone sheet below ground floating grillage concrete floors with Hebel infill walls

embodies climate responsive design, solar hws, photovoltaics with grid connect inverter, rain water, Wisconsin mound, conservatory, clerestory, ventilated pantry, solar drying cupboard   The Packer family have built for themselves a home during 2001 which draws on many of the features already previously developed in houses from this practice. The site is a rural living allotment on the north-east outskirt of the small town of Mundulla, 10km south-west of Bordertown in South Australia's South-East. The land has an open north aspect on level open ground, with the existing mature vegetation and town cemetery abutting to the south. The site issues are the very heavy black clay soils with their poor water absorption and the large summer to winter soil surface movement. The design of the house reflects these design priorities. The floor plan is three pavilions, where the roof is supported on overarching steel portals which span clear of the building wall perimeter. The portals are set on piers seated on the sub surface limestone sheet horizon below ground level. This approach ensures that the roof and structural frame of the house are stable. The separate and inset grillage concrete floor rafts for each section of the house in contrast are intended to bob up and down independantly with the soil movement. The infill Hebel walls have gaps to the roof above. In this way there is no heave load on the wall or roofs, and little chance of cracking. This approach is the opposite to traditional engineering goal to increase the rigidity of the structure to resist movement. The zen 'go with the flow' approach as opposed to the colonialist domination theory. The house features many of this practice's standard components. Standard steel cold rolled portals as the primary structure, in this case braced with visible rod and tube cross braces. Steel roof sheet with over purlin insulation and sarking, suspended ceilings with insulation. The wall insulation is contained in the 200mm wide aerated autoclave concrete. The concrete floors provide thermal mass. Roof water is collected for in-house potable use. Waste waters are sent via treatment tank to disposal. Because of the poor absorption of these soils, a 'Wisconsin Mound' has been built. The mound takes pressure injected waste water into holding pipe and gravel to allow constant water application into the sand mound onto the raked clay surface. The intent is to maximise the water take up into the soil, and to vegetation for transpiration. A top clay layer on the mound avoids winter stormwater in seepage. The house contains the normal passive systems including conservatory and clerestory. This is extended in this house with a north frontage facing passive clothes drying cupboard within the conservatory glass front; and ventilated pantry in the kitchen. Power demand is contained as it is in the other projects from this practice. Switches have indicator lights. Power supply is the photovoltaic system on the centre roof, which is mains power grid connected via grid interactive inverter. Hot water is produced by solar hot water system with gas boost. The building layout follows passive principles, with north orientation, western side shaded, roof overhang shading summer sun out but allowing winter warming sun in. The climate response systems of cross ventilation by warming and wind flow over the roofs are incorporated.